1. Look at the existing Player_*.zip files for information on this. For the names and default values of the attributes you can edit of a player type (e.g. maxRunSpeed, jumpForce) , put PlayerStandardArmor.dump(); into the console while hosting a game, or a single player server. Always edit the uiName and datablock names of the player types you create, this prevents them overwriting each other or mixing up in the Minigame/event menus.
2. Look at the existing Particle_Basic.zip file for examples of various emitters, including a fire emitter.